Drive device for a movable furniture part

ABSTRACT

The invention relates to a drive device for a movable furniture part, comprising two ejecting devices arranged on opposite sides of the movable furniture part for ejecting the movable furniture part from a closed position to an open position. The ejecting devices each comprise a spring-loaded locking element for locking the ejecting device in a locking position, a guide track having an angled end segment, wherein the locking element can be locked in the locking position in the angled end segment, and a release element separate from the locking element, by means of which release element the locking element can be released from the angled end segment into an overpressing position lying behind the closed position when the movable furniture part is overpressed, and a synchronizing device, by means of which the release elements of the two ejecting devices can be synchronized.

The invention concerns a drive device for a movable furniture part, comprising two ejection devices for ejecting the movable furniture part from a closed position into an open position, wherein the ejection devices are arranged on opposite sides of the movable furniture part and wherein each ejection device comprises a spring-loaded locking element for locking the ejection device in a locking position, a guide track comprising an angled end section, wherein in the latching position the locking element can be locked in the angled end section, and a release element being separate from the locking element, wherein the locking element can be released from the angled end section by the release element into an overpressing position lying behind the closed position when the movable furniture part is overpressed. Moreover, the invention concerns an item of furniture with such a drive device.

Such a drive device is disclosed in the DE 10 2010 061 482 A1. It concerns primarily the opening and closing operation of a movable furniture part, wherein the locking of the ejection device is effected in an angled end section of a guide path. It is disadvantageous with this known opening and closing device and drive device respectively that especially when being applied with broad drawers, an oblique positioning and a one-sided unlocking can occur by one-sided triggering or overpressing the drawer. This can lead to an undesired jamming of the drawer in the furniture carcass.

Therefore, one object of the present invention is to prevent these problems. For this reason the present invention also concerns a synchronizing device.

Generally, miscellaneous synchronizing devices are already known from the prior art. A first example for synchronized ejection devices is disclosed in the EP 1 314 842 B1, according to which the disengaging levers are connected to each other synchronously and free from play. Notching extensions—which form the locking element—are arranged on these disengaging levers. These notching extensions are locked in a latch which forms a kind of a guide path for the notching extensions. An unlocking of the notching extension from the latch takes place by a movement of these two parts relative to each other when overpressing. There is no release element which is separate from the latch or from the notching extension.

A further lockable ejection device with a synchronizing unit is disclosed in the WO 2009/114884 A2. Here, an extension formed on a receiving element is movable and lockable in a heart curve-shaped sliding guide track. Also in this example the unlocking is effected by a movement of these two components relative to each other when overpressing, whereupon an ejection force storage means can relax and the movable furniture part is ejected into opening direction.

Also according to the EP 2 429 339 B1 the locking is effected via a heart curve-shape sliding guide track, wherein a latching element supported on a movable slider engages with the heart curve-shaped sliding guide track. Also here the unlocking is effected by a relative movement of the latching element to the heart curve-shaped sliding guide track. The synchronization is carried out by coupled motions of the linearly movable sliders.

A further locking of this kind is disclosed in the WO 2013/059847 A1.

In contrary, the DE 20 2009 005 255 U1 discloses a synchronizing without a specific mechanic synchronizing unit. Rather, the synchronizing is effected by a power transmission via the drawer to the other side, so that the not yet released locking element is released by the double-acting force of the ejection force storage means in pulling direction. Thus, also here the unlocking is carried out by a movement of the switching element relative to a switching curve.

Another synchronizing method is disclosed in the not pre-published Austrian Patent Application A 785/2013. Here, a synchronizing is conducted only after the overpressing movement, as a part of the guide track of the not released ejection device is moved via the synchronizing device when the ejection of the other ejection device has already begun, whereby the latching peg locked in a latching recess can be moved out of this latching recess of the heart curve-shaped sliding guide track. Also here, thus, an unlocking is carried out by a relative movement between the heart curve-shaped sliding guide track and the latching peg.

If now a person skilled in the art has the object to implement a known synchronizing device in the known DE 10 2010 061 482 A1, the person skilled in the art could take instructions from the prior art in order to synchronize, for example, the movements of the locking elements, the movements of the ejection devices or the movements of parts of the guide track of the two ejection devices.

The object—to prevent an oblique positioning of the drawer in the case of a drive device according to the DE 10 2010 061 482 A1—according to the invention is attained in that the release elements of the two ejection devices can by synchronized with the synchronizing device. Thus, a possibility for a synchronization is established which is not obvious from a combination of the mentioned documents, especially as there is no release element separate from the locking element and from the guide track in all of the synchronizing devices known from the prior art.

Further preferred embodiments are indicated in the sub-claims.

For example it is preferably provided that each ejection device comprises a housing. For a simple construction it is provided that the guide tracks are each formed in the housing. For a more simple ejection movement the guide tracks each comprise besides the angled end section also an ejection section.

Basically, the release elements can be movable linearly. Particularly preferred, however, it is provided that the release elements are each movably, preferably pivotally, supported at the housing.

A synchronization of the release elements can be conducted for example via a rotatable synchronizing rod which for example engages via sprockets formed at the end of the rotatable synchronizing rod with toothed rods formed at the release elements. Preferably, however, it is provided that two bearing positions are formed on each release element and synchronizing rods of the synchronizing device are rotationally supported at these bearing positions. Particularly preferred, these synchronizing rods are arranged crossed over so that a rotational movement of one of the release elements is transformed in a reverse rotational movement of the other release element.

For an easy guiding of the locking elements it is provided that the locking elements are each supported slidably in the guide track via two peg-shaped extensions.

In principle, the drive device can only consist of the two ejection devices and the synchronizing device. However, for still more variegated applications a retraction device for retracting, preferably in a damped manner, the movable furniture part form an open position into the closing position is provided preferably additional.

Moreover, protection is sought for an item of furniture with a furniture carcass, a movable furniture part and a drive device according to the invention. In such an item of furniture the drive device can be associated to the furniture carcass. This means, the two drive devices are mounted on opposite sides of the movable furniture part, for example directly on the furniture carcass or on a carcass rail of an extension guide. Preferably, however, it is provided that the drive device is arranged on the underside of the movable furniture part, wherein each ejection device can be coupled in sections via an ejection slider with an engaging member being fixed to the furniture carcass. This means, the drive device so to speak pushes itself away from this engaging member being fixed to the furniture carcass. In these embodiments the retraction device can be integrated into the extension guide.

Further details and advantages of the present invention are described more fully hereinafter by means of the specific description with reference to the embodiments illustrated in the drawings, in which:

FIG. 1a shows an item of furniture with a movable furniture part and a drive device,

FIG. 1b shows a movable furniture part with a drive device,

FIG. 2 shows an exploded view of a drive device,

FIG. 3 shows a 3D-view of the assembled drive device and

FIGS. 4 to 14 each show in a top view the function sequence of the movements of the drive device.

FIG. 1a shows an item of furniture with a furniture carcass 16 and two movable furniture parts 2 built as drawers. These drawers each comprise a drawer box 22 and a front panel 21. The movable furniture parts 2 are movably supported at the furniture carcass 16 via extension guides. These extension guides comprise at least one carcass rail 19 and one drawer rail 20. A drive device 1 is arranged on the bottom of the movable furniture part 2. The drive device 1 comprises two ejection devices 3 arranged on opposite sides of the movable furniture part 2 as well as a synchronizing device 8. Engaging members 18 are arranged on the carcass rails 19.

FIG. 1b shows the bottom of the movable furniture part 2 with the drive device 1 at least partly mounted to the movable furniture part 2. This drive device 1 also comprises a retraction device 14 for retracting the movable furniture part 2 from an open position OS into a closed position SS, which retraction device 14 is arranged in or at the extension guide. In this embodiment the retraction device 14 is mounted to the drawer rail 20 and can be coupled with the engaging member 38 arranged at the carcass rail 19. Moreover, the attachment of the engaging member 18 at the carcass rail 19 via a holding plate 37 is recognizable.

The drive device 1 in a partial exploded view is apparent in FIG. 2. As already apparent in this FIG. 2, the two ejection devices 3 are each formed mirror-symmetrically. Basically, however, slight differences could of course exist between the two ejection devices 3. For an easier production, however, the ejection devices 3 are formed identically or exactly mirror-symmetrically. Each of the ejection devices 3 comprises a housing mountable to the movable furniture part 2. The guide track 5 with the ejection section 10 and the angled end section 6 is formed in this housing 9. Moreover, the guide track 30 for the extension 29 formed at the locking element 4 and the guide track 25 for the ejection slider 17 are formed in the housing 9. The ejection slider 17 is linearly movable along this guide track 25. The ejection slider 17 comprises the coupling extension 23 via which the ejection devices 3 can each be coupled with the engaging member 18 being fixed to the furniture carcass. The detents 27 are movably supported via pressure springs 28 at each ejection slider 17. The locking element 4 is movably supported in the guide track 5 via the two extensions 13. The other extension 29 of the ejection element 4 engages into the guide track 30. The ejection force storage means 24 formed as a tension spring is kept on the one side at the extension 29 of the locking element 4 and on the other side at the spring base 33 formed at the housing 9. The release elements 7 are formed separately from the guide tracks 5 and from the locking elements 4. The release elements 7 are also movable relative to the guide tracks 5 and to the locking elements 4. The release elements 7 are rotationally supported via rotary bearings 31 in the recesses 35 formed in the housing 9. Further, bearing positions 11 are formed in each of the release elements 7, in which bearing positions 11 the extensions 32 of the synchronizing rods 12 engage. The synchronizing device 9 is built by these synchronizing rods 12 with the extensions 32 formed thereon in collaboration with the bearing positions 11 at the release elements 7. The damping element 26 serves for a smooth deceleration or damping of the ejection movement of the locking element 4.

In FIG. 3 the drive device 1 is depicted in an assembled condition in the case of a relaxed force storage means 24. As apparent, the two synchronizing rods 12 are arranged crossed-over in different heights.

The top view of the drive device 1 according to FIG. 4 corresponds to the 3D view according to FIG. 3. If this drive device 1 is arranged on the underside of the movable furniture part 2, according to FIG. 4 still no contacts exists to the schematically depicted engaging members 18 being fixed to the furniture carcass. Thus, the movable furniture part 2 is situated in the open position OS.

If the movable furniture part 2 is manually moved from the position according to FIG. 4 into closing direction SR, the coupling extensions 23 of the two ejection sliders 17 reach contact with the engaging members 18. As these engaging members 18 are stationary, the ejection sliders 17 are moved relative to the housings 9. As also the locking elements 4 abut the detents 27 formed at the ejection sliders 17 via the noses 34, also the locking elements 4 are moved relative to the housings 9 along the guide tracks 5. As the force storage means 24 are held at the extensions 29 of the locking elements 4, the force storage means 24 are tensioned in the case of this movement into closing direction SR.

In FIG. 6 this tensioning process has further continued. The movable furniture part 2 is still situated in an open position OS.

According to FIG. 7 the movement of the movable furniture part 2 into closing direction SR has further continued, so that the locking elements 4 reach the angled end sections 6 of the guide tracks. With reaching the angled end sections 6, the two locking elements 4 each contact the release elements 7, so that these release elements 7 correspondingly rotate about the rotary bearing 31. These rotational movements of the release elements 7 are synchronized by the synchronizing device 8.

In FIG. 8 the locking elements 4 have reached the end of the angled end sections 6 of the guide tracks 5. Thereby, the locking elements 4 are kept in the guide track 5 because of the inclination and the friction of the extensions 13. Thus, the force storage means 24 cannot relax. In this position of the locking elements 4, the two ejection devices 3 are each situated in the locking position VS. According to FIG. 8, due to a retraction device 14 (not shown) the two ejection sliders 17 have already been moved further into closing direction SR till the closing position SS of the movable furniture part 2 is reached. In this closing position SS the detents 27 each abut the extensions 36 of the release elements 7.

If the movable furniture part 2 is overpressed into closing direction SR starting from this closing position SS according to FIG. 8, the movable furniture part 2 reaches an overpressing position OS according to FIG. 9. In this overpressing position OS the ejection sliders 17 are further moved relative to the housings 8 due to the collaboration with the engaging members 18 fixed to the furniture carcass, so that via their extensions 36 the release elements 7 are rotated by the detents 27 about the rotary bearings 31. Should here, in the event of this overpressing movement, the movable furniture part 2 be pushed only one-sided, so only on this side the release element 7 is actively moved or rotated by the detent 27. But yet also a movement of the release element 7 is effected each time on the opposite side, namely by the synchronizing movement via the two synchronizing rods 12. With this rotational movement of the two release elements triggered by the overpressing movement, both locking elements 4 are moved or released substantially at the same time and, thus, synchronously from the angled end section 6. Therefore, the locking position VS is unset, the locking elements 4 are not anymore kept in the angled end sections 6 and the two ejection force storage means 24 can begin to relax.

Due to this ejection process shown in FIG. 10, the locking element 4 is moved along the ejection section 10 of the guide track 5. Also the ejection slider 17 is carried via the nose 34, so that the ejection devices 3 are pushing themselves away from the engaging member 18 fixed to the carcass. The movable furniture part 2 is thereby moved into opening direction OR, so that the movable furniture part 2 again reaches an open position OS. Also a retraction device 14 (not shown) can be loaded simultaneously with this ejection process.

In FIG. 11, this ejection process has already further progressed but is not yet finished.

In FIG. 12 the ejection process is completed and the force storage means 24 are relaxed. At the end of the ejection movement the locking elements 4 touch the damping elements 26. The ejection sliders 17 are further moved along the guide track 25 by the momentum or by a manual onward movement, whereby the detents 27 reach contact with the noses 34 of the locking elements 4.

Then, the detents 27 are moved relative to the ejection sliders 17 against the force of the pressure spring 28 (see FIG. 13).

In FIG. 14 also the movements of the ejections sliders 17 are completed and the detents 27 have driven over the noses 34. The ejection devices 3 do not anymore abut the engaging members 18 being fixed to the carcass via the coupling extensions 23, so that the movable furniture part 2 is situated in an open position OS, in which the movable furniture part 2 can be moved freely by hand. The starting position according to FIG. 4 is reached again. 

1. A drive device for a movable furniture part, comprising two ejection devices for ejecting the movable furniture part from a closed position into an open position, wherein the ejection devices are arranged on opposite sides of the movable furniture part and wherein each ejection device comprises a spring-loaded locking element for locking the ejection device in a locking position, a guide track comprising an angled end section, wherein in the latching position the locking element can be locked in the angled end section, and a release element being separate from the locking element, wherein the locking element can be released from the angled end section by the release element into an overpressing position lying behind the closed position when the movable furniture part is overpressed, and a synchronizing device, by means of which the release element of the two ejection devices can be synchronized.
 2. The drive device according to claim 1, wherein each ejection device comprises a housing.
 3. The drive device according to claim 2, wherein the guide tracks are each formed in the housing.
 4. The drive device according to claim 1, wherein each guide track comprises an ejection section.
 5. The drive device according to claim 2, wherein the release elements are each movably, preferably pivotally, supported at the housing.
 6. The drive device according to claim 1, wherein two bearing positions are formed on each release element, wherein synchronizing rods of the synchronizing device are rotationally supported at these bearing positions.
 7. The drive device according to claim 1, wherein the locking elements are each supported slidably in the guide track via two peg-shaped extensions.
 8. The drive device according to claim 1, comprising a retraction device for retracting, preferably in a damped manner, the movable furniture part from an open position into the closed position.
 9. An item of furniture comprising a furniture carcass, a movable furniture part and a drive device according to claim
 1. 10. The item of furniture according to claim 9, wherein the drive device is arranged on the underside of the movable furniture part.
 11. The item of furniture according to claim 9, wherein each ejection device can be coupled in sections via an ejection slider with an engaging member being fixed to the furniture carcass. 